They seem innocent enough, but many a motorist has suffered damage caused by "invisible" potholes, and a road maintenance website has warned accidents are on the rise.
Heavy snow, sleet and frost over the past weeks have hidden potholes under a blanket of slush in many parts of the country, and combined with longer hours of winter darkness more drivers are failing to spot the small craters.
According to Potholes.co.uk, which was set up by automotive warranty provider Warranty Direct, water-filled cavities in the road are more dangerous -and costly - than people think.
Warranty Direct's Duncan McClure Fisher said: "The icy conditions over Christmas and the New Year have created new potholes across the country and motorists need to watch out.
"Treacherous ice and snow may be at the forefront of drivers' minds as the main hazard, but potholes are another danger they need to be aware of."
The UK's 30 million motorists spend about £1 million everyday repairing pothole damage, at an average of £240 a time, according to Warranty Direct. Experts have estimated the number of defects on English roads rose 65% in the past decade.
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